Driving mechanism



March 30,1937. w, ALLEN 2,075,078

DRIVING MECHANISM Original Filed Jan. 28, 1932 IN VEN TOR. Jose pl: WA/len Patented Mar. 30, 1937 PATENT: OFFICE DRIVING MECHANISM Joseph W.Allen, East Orange, N. 1., assignor, by

mesne assignments, to Eclipse Aviation Corporation, East Orange, N. J.,a corporation of New Jersey Original application January 28, 1932,Serial No. 589,516. Divided and this application January 26, 1933,Serial No. 653,747

7 Claims. (c1. 192-48) This invention relates to driving mechanism, andparticularly to driving mechanism of the type adapted to transmit torquein one direction only and permitting relative rotation between thedriving and driven members.

Although not limited to such use, the present invention has for one ofits objects an improvement in driving means heretofore-employed fordrivably connecting ,an internal combustion engine and a generator ofelectrical energy for use in radio equipment and other electricityconsuming devices on a vehicle such as an airplane in which saidinternal combustion engine is installed.

Generators of this character have been used heretofore on vehiclesequipped with radio transmitting apparatus, particularly aircraft; andwhen so employed, in addition to the mechanical driving means, suchgenerators have in certain instances been equipped with electricalconnections to a battery or equivalent source of electrical energywhereby the generator may be operated as a motor generator or dynamotorso as to continue supplyingcurrent to a radio trans: mitter or otherload, notwithstanding a de-energization or disabling of the aircraftengine. When so operated the device has been provided with overrunningclutch mechanism, permitting relative rotation between the armatureshaft and the engine driven member when the engine is at rest, while atthe same time afiording a positive drive while the engine is running.When such an overrunning clutch constitutes the sole driving connectionbetween the engine and the generator, the

latter is subjected to the shocks and speed fluctuations characteristicof an internal combustion engine, which-shocks and fluctuations areobviously objectionable, particularly when the load being suppliedby'the generator is one which requires the maintenance of constantvoltage output from the generator.

Accordingly one of the objects of the present invention is to provideimproved operating connections between driving and driven elements, suchas an engine and an electrical unit driven thereby, said novelconnections embodying features, the use of which serve to eliminate thedisadvantages above referred to. By way of illustration of this phase ofthe invention, two embodiments are herein shown, one of which involvesthe use of a combined flexible coupling, speed responsive clutch andone-way clutch in a single unit adapted to produce both overrunning andyielding actions, and the second also providingflexible and overrunningfeatures.

Another object of the invention is to provide a flexible couplingemploying one or more pairs of shock absorbing springs or equivalentresilient elements characterized by the fact that one resilient elementof each pair acts to cushion sudden accelerative impulses ,ot thedriving ;ielement, while the other of each pair acts to eliminate, orat, least minimize, the objectionable backlash which is characteristicof many flexible couplings heretofore used.

These and other objects and advantages to be derived from the use of theinvention disclosed herein will become evident on a consideration of thefollowing description when read with reference to the accompanyingdrawing illustrating line 2-2 of Fig. 1;

Fig. 3 is a transverse section taken along the line 3-3 of Fig. 1;

Figs. 4 and 5 are sectional views of a second novel coupling;

Fig. 6 is aplan view of an internal combustion engine power plant .withone embodiment of the present invention applied thereto.

Referring to Figs. 1, 2, 3 and 6 the invention is therein shown asembodying a device having a central hub portion 10 that is mounted onthe armature shattoi a generator 5 constituting part of the internalcombustion power plant indicated at 6 in Fig. 6, and is adapted torotate with said armature shaft, being suitably retained thereon as bymeans of a threaded nut "H. In the form shown, the hub 10 has eyes 12which extend substantially at right angles to the plane or the centralportion I0, the inner walls of the openings in each eye being threadedto receive exteriorly threaded cup-shaped members or holders ll.Preferably the outer end of each holder is slotted to receive asuitable, adjusting tool.

Extending into each or the cups is one end of a compression coil springI5 of any suitable type. The opposite ends of springs I5 engage oppositefaces of an intermediate coupling member 19 which is integral with thebored coupling member 80, the latter having a splined portion 56 adaptedto receive a gear 55 driven from the crankshaft of the engine 6 throughconnecting gearing indicated at 55' in Fig. 6. As shown in Fig. 3, thefaces of the coupling member I9 are 5 out at an angle to the center linethereof so as to be normal to the axes of the springs engagingtherewith, the latter being disposed along lines approximatelytangential to the central hub portion 10.

The overrunning portion of the coupling includes a plurality of rollers8| adapted to be held by a. resilient cap 8la between a correspondingnumber of radially extending portions 82 formed at regularly spacedintervals about the periphery of an inner race 83 splined to thearmature shaft 5 as indicated at 84. As shown best in Fig. 2, theserollers are normally maintained in engagement with the inner surface ofthe hub 10 by resilient means, such as springs 85, so that, as. memberIll rotates in a clockwise direction, rollers 8| will be effective torotate the driven member 83. However, if it is attempted to transmittorque from member 83 to member ID in the same direction of rotation,the rollers 8! will 25 become inefiective.

From the foregoing it is apparent that as driving torque is transmittedfrom the engine to the coupling member 80, one spring of each of thepairs acts yieldingly to transmit the driving force 30-to the armatureshaft 5, and at the same time to cushion the shocks 'due to changes inthe engine speed, while the other spring 15 of each pair serves tocushion the subsequent rebound action of the coupling member 19 and thuseliminate, or at least substantially minimize, the backlash which wouldotherwise result. The compression of springs 15 is positively limited bythe engagement of the adjacent ends of holders I4 and I9, prior to totaldeflection of the springs, and by 40 suitably adjusting said holders theload deflection characteristics of the connection may be varied withinwide limits. Moreover the inertia of the armature is yieldable overcomeby the flexible coupling without sudden jars or shocks.

45 The construction is particularly adapted for use in connection withairplane engines wherein no flywheel is provided, and wherein the enginevibration and sudden starting and stopping of the engine is likely toseriously damage or disso rupt the driving connection between thegenerator and the engine, if said connection is non-yielding.

Figs. 4 and 5 show a second form of driving connection which may beemployed, this form embodying the flexible and overrunning features 5'5of the coupling shown in Figs. 1, 2 and 3, but adding thereto acentrifugal factor, obtained by substituting for the holders "of Figs.1, 2 and 3,

a pair of friction shoes 90 and 9| adapted to be maintained in firmfrictional contact with the my inner surface of, a drum 51 by the actionof springs 15', one pair of which are adapted to absorb shockstransmitted in one direction by yielding in the manner indicated in Fig.5, and the other being adapted to absorb shocks trans- 55 mitted in theopposite direction. It will be noted however, trifugal force, act tomaintain the shoes in frictional contact, and the torque transmittingcapacity of theolutch will accordingly depend in 7 part upon the sizeand setting of the said springs. Preferably the central driving member19' is driven from the engine or other mechanical driving means whilethe drum constitutes the outer race of an overrunning clutch assemblypreferably taking the form of that shown in Figs. 1

that all four springs, as well as cen-.

and 2, the provision of such an overrunning clutch mechanism beingoperative to prevent any frictional wear between the shoes 90 and 90 onthe one hand, and the drum 51 on the other, during the time theelectrical unit is being operated from the battery as a motor generator.

With this construction it is apparent that as the engine approaches itsnormal speed the centrifugal force acting upon the shoes 90 and M willcause them to establish firm contact with the inner surface of the drum51 while at the same time permitting a slipping of the shoes along saidsurface in the event of excessive shocks being imparted to said shoesthrough the engine driven connections. As soon as the shoes haveabsorbed the shock thus imparted, the shoes again resume positivefrictional association with the drum and thus maintain the latter at aconstant speed of rotation without presenting thereto the excessiveshocks and vibrations of the engine. The roller clutch acts to break thedriving relationship and thus prevent a return torque transmission tothe engine driven members from the generator, when the latter isoperated as a dynamotor.

Having thus described several of the important embodiments of thepresent invention, it is to be understood that various otherconstructions may be employed without departing from the spirit of theinvention, so long as the variations are within the scope of theappended claims. Reference will therefore be had to these claims for adefinition of the limits of the invention.

This is a division of my Patent No. 1,921,719 granted August 8, 1933,filed January 28, 1932.

What is claimed is:

1. In a driving mechanism for use with an internal combustion engine andan auxiliary engine unit, the latter being adapted to be energized bysaid engine and by means independent of said engine at differentperiods, the combination with said engine, of a driving memberpositively connected with the engine, and rectilinearly movable speedresponsive means for frictionally connecting said driving member withsaid auxiliary engine unit, said speed responsive means includingresilient means also serving to cushion the drive from said drivingmember to said auxiliary engine unit, said resilient means also servingto maintain a certain degree of frictional pressure upon said auxiliaryengine unit regardless of speed.

2. In combination, in-a device of the class described, a driving member,a driven member, a friction clutch connecting said members including aplurality of friction shoes subject to centrifugal force, a plurality ofsprings also tending to hold said shoes in driving relation to thedriven member, said springs being yieldable to provide flexibility inthe drive, a drum adapted to be engaged by said friction shoes, and anoverrunning clutch whose outer race is integrated with said drum andwhose inner race is integrated with said driven member.

3. A clutch for driving and driven shafts comprising a driving membercarried on the driving shaft and having a pair of oppositely extendingaligned arms, a speed responsive member adjacent said driving member andhaving a plurality of recesses therein, resilient means mounted in saidrecesses for transmitting torque from one to the other of said members,said members being adapted to directly engage for transmission ofdriving torque independently of said resilient means upon application ofa predetermined torque, and said resilient means being received in saidrecesses and compressed less than the full amount of which they arecapable during direct engagement of said members.

4. A clutch for driving and driven shafts comprising a driving membercarried on the driving shaft and having a. pair of oppositely extendingdiametrically'aligned arms, a slidably mounted member adjacent saiddriving member and having a plurality of recesses therein, resilientmeans mounted in said recesses for transmitting torque from one to theother of said members, said members being adapted to directly engage fortransmission of driving torque independently of said resilient meansupon application of a predetermined torque, and said resilient meansbeing received in said recesses and compressed less than the full amountof which they are capable during direct engagement of said members.

5. In a driving mechanism for use with an internal combustion engine andan auxiliary engine unit, the latter being adapted to be energized bysaid engine and by means independent of said engine at difierentperiods, the combination with said engine of a one-way drivingconnection interposed between said engine and unit, said one-way drivingconnection including an inner race positively connected with said unit,an outer race coaxial therewith, a driving member positively connectedwith the engine, and yieldable shock absorbing means acting alongparallel lines tangential to a common circle.having its center in theaxis of rotation of said one-way driving connection.

6. In a power drive, a splined shaft, an overrunning clutch hub splinedto the shaft, an overrunning clutch housing, uni-directional clutchelements disposed between the housing and hub, a driven clutch plate, adriving clutch plate to impart rotary movement to the driven clutchplate, and a plurality of springs acting along parallel lines tangentialto a common circle having its centerin the axis of rotation of saidplates to form a resilient connection between said plates.

7. In a device of the class described, a driving member, a drivenmember, a friction clutch connecting said members including a. pluralityof friction shoes and a drum engaged by said shoes, resilient means fortransmitting the drive from said driving member to said friction shoesand an overrunning clutch having an outer race integrated with said drumand an inner race integrated with said driven member.

JOSEPH w. ALLEN.

